Spring-coiling machine



June 3, 1930.

- M. NlgRo 1,761,739

SPRING COILiNG MACHINE Filed Nov. 1. 1928 2 Sheets-Sheet '1.

M76724 jig/'0 June 3, 1930. Y M, eRo 1,761,739

SPRING COILING MACH-INE Filed Nov. 1, 1928 2 Sheets-Sheet 2 .1 a Mk6!Jay/0 Patented June 3, 1930 UNITED STATES PATENT OFFICE MICHEL NIGRO, OFWORCESTER, MASSACHUSETTS, ASSIGNOR TO SLEEPER & HARTLEY, INC, OF,WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTSSPRING-OOILING' mcnmn My invention relates to machines for forming orcoiling wire springs, particularly coiling machines of the typeemploying feed rolls for positively feeding the wire to a stationarycoiling point where it is deflected around an arbor into a coil of thedesired size and form.

A machine of this general type is shown and described in Patent No.1,266,070 issued May 14, 1918, to Frank H. Sleeper, and the object ofthe present invention is to provide a spring coiling machine of thistype with an improved arbor and coiling and cutting instrumentalitiesco-operating therewith whereby springs may be coiled and out having avery much smaller internal diameter than any springs that it has beenheretofore possible to coil and cut on existing machines. Furthermore,my improved arbor is so designed that it possesses very great strengthfor its size and is able to withstand the strains imposed upon it by theimpact of the cutting tool each time a spring is severed. The above andother advantageous features of my invention will hereinafter more-fullyappear with reference to the accompanying drawings in which- Fig. 1 is ageneral View in front elevation of a portion of a spring coiling machineprovided with an arbor and tools embodying my invention.

Fig. 2 is a fragmentary view illustrating on an enlarged, scale thespring coiling and cutting tools co-operating with my improved arbor.

Fig. 3 is a horizontal sectional view along the line 3-3 of Fig. 1,looking in the direction of the arrow.

Fig. 4 is a perspective view of the tool holder with my improved arborcarrled thereby. I

Figs. 5, 6 and 7 are enlarged detailed vlews of the arbor removed fromits holder.

.Fig. 8 illustrates the formation of a coil on the arbor.

Fig. 9 is a perspective View of the coiling point removed from themachine.

Fig. 10 is aperspective view of the pitch tool removed from the machine.

Like reference characters refer to like parts throu bout the drawings.

Re erring to the drawings, particularly Fig. 1, the machine generallycomprises a housing upon which are mounted airs of co-operatlng feedrolls 2, 2 and 3, 3 w ich are adapted by their rotation to grip the wire4 and positively feed it through grooved wire guides 5 and 6 to thecoiling tools.

' The particular mechanism for driving the' rolls 2 and 3 to feed thewire 4 forms no part of the present invention, but is fully shown anddescribed in the aforesaid Sleeper Patent N 0. 1,266,070. Sufiice it tosay for the purposes of the present invention that the two pairs of feedrolls 2 and 3 are geared together for synchronous, rotation and areriven intermittently from a suitable source of power to feed the wire 4step by step to the coiling devices which will now be described.Referring now to Fi 2 it will be seen that as the wire 4 emerges rombetween the lefthand guides 6 under the urge of the feeding rolls2 and3, it will be partially received in a groove 7 provided in the loweredge of an auxiliary guide 8. The wire 4; will then pass over thecoiling nose 9 of my improvedarbor 10 to the coiling point 11 which willdeflect the wire downwardly around thenoee 9 when a righthand spring isbeing coiled. As the wire is fed and coiled on the arbor 10, the properpitch is imparted to the convolutions of the helix by a pitch tool 12.

When enough wire 4 has been fed by the rolls 2 and 3 to form a coil ofthe desired length, the rotation of the feed rolls 2 and 3 isinterrupted, whereupon a cutting tool 13 severs the completedcoil byco-operation with the stationary arbor 10. As fully described in theaforesaid Patent No. 1,266,070, the cutting tool 13 is carried by aclamp 14 on a movable head 15 that is adapted to have a 'rotativemovement imparted thereto to swing the cut-- ting tool 13 in thedirection of the arbor 10, the mechanism for operating the head 15 beingso timed as to operate the cuttin tool 13 as soon as the wire feedingrolls 2 an 3 come to rest.

The holder 16 provides a longitudinal open ing 17 for receiving thearbor 10 and a second opening 18 parallel to the opening 17 receivesa.rod 19 for supporting the pitch tool 12. The holder 16' also provides athreaded opening 20 for receiving a bolt '21 which secures the auxiliaryguide 8 to the face of the holder 16. ,7 I I Referring now to Figs. 5, 6and 7, the arbor 10 consists of a cylindrical body portion of suitablediameter to be received in the opening 17 of the tool holder 16, a slot17 intersecting the opening 17 to permit the material of the holder tobe compressed around the cylindrical body portion of the arbor 10 tohold it firmly in position. Each end of thearbor 10 provides a web 22 ofuniform thickness, the parallel faces 22 of the web 22 being joined atone end of the web 22 by a rounded surface 23 which extends at rightangles to the end face 24 of the arbor body. The coiling nose 9 isformed at theend of the rounded surface 23 by beveling the edge ofthe,web 22 to. provide a shoulder 25 around which the wire is deflectedas shown in. Fig. 8, when forming the smallest coil. The bevel 26 mergesat one end of the web 22 with the rounded surface of the cylindricalbody portion, the bevel serving to direct the wire as it passes aroundthe nose 9 when forming coils of difierent diameters. By reason of theconstruction of the nose 9 it is possible to form a coil, the internaldiameter of which is not more than one and one-half times the diameterof the wire from which the coil is being formed, as shown in Fig. 8.

It is also apparent from -aconsideration of Fig. 5 that the constructionof the arbor 10 is such as to provide the maximum degree of strength forthe nose 9 on which the coiled wire is cut by the tool 13 strikingthrough to the sharp edge 27 between the rounded end surface 23 and thelower flat web face 22.

. The web portion extending across the arbor face 24 has a lengthseveral times the diameter of the nose 9 so that the whole area at thebase of this web 22 will have to be sheared off in order to break offthe nose 9 when it receives the impact of the cutting tool 13. The arbor10 is provided with a web 22 at each end, thenoses 9 facing in oppositedirections so that when the arbor 10 is reversed, the nose 9 will faceproperly for the formation of a 'left-hand coil. v

As best shown in Fig. 10, the pitch tool 12 is adapted to be set closelyto the Web 22 of the mandrel 10 when coiling springs of small diameter,the upper edge of the tool 12 providing a depression 28 which is adaptedto receive a portion of the web 22 when the pitch tool 12 is turned onits supporting rod 19 in the position shown in Fig. 2. The position ofthe pitch tool 12 with respect to the arbor 10 and coiling point 11 isadapted to be controlled in the manner set forth in the aforesaid PatentNo. 1,266,070'and it is therefore believed to be unnecessary to go intofurther detail regarding this particular mech-' anism which forms nopart of the present invention.

Referring now to Fig. 9 the coiling point 11 is shown provided with agroove 29 at each end thereof to receive the wire 4 as it is deflectedaround the coiling nose 9, each end of the tool. 11 being beveled in twoplanes to provide clearance for the cutting-tool 13 to swing in close tothenose 9 when severing a completed spring. The coiling point 11 issecured by a clamp 30 to a block 31 which is carried by a pin 32projecting from a slide 33 as shown in Fig. 3. The slide 33 is adaptedto be moved with respect to the arbor or man drel 10 by means of an arm34 for the purpose of varying the diameter of the springs being coiled.

From the foregoing, it is apparent that by my invention I have provideda spring coiling.

machine embodying an improved arbor on which springs of very smalldiameter may be coiled and out. By means of my arbor it is possible tocoil and cut springs which have an internal diameter of not more thanone and one-half times the diameter of the wire stock being coiled.Furthermore, my improved arbor is so constructed that the nose aboutwhich a wire is actually coiled is formed integrally with a web whichserves to' around which wire is adapted to be de ected into a spiralhaving an internal diameter of less than twice the diameter of the wirebeing coiled.

2. In a machine of the class described, a coiling arbor providing at itsend a projecting web having a rounded end and parallel faces, one ofsaid faces being beveled to provide a shoulder opposite to said roundedend around which shoulder the wire is deflected in coiling.

3. In a machine of the class described, a coiling arbor providing at itsend a projecting web having a rounded end and parallel faces, one ofsaid faces being beveled to provide a shoulder around which the wireisdeflected in coiling, with the junction between said beveled face andsaid rounded end probe severed.

4. In amachine of coiling arbor comprisinga cylindrical body whichprovides a web of portion, one end of substantially unifor the classdescribed, a

thickness, the parallel faces of said web being joined at one end by 5 arounded surface extending at right angles to the end face of the a faceof the web beveledrbor body, with one to provide a'shoulder around whichthe Wire is deflected in coilmg.

MICHEL NIGRO.

